The invention generally relates to skateboards, and relates in particular to truck assemblies on skateboards.
Skateboard truck assemblies generally include the skateboard wheels, axle and mounting hardware the attaches the wheels and axle to the underside of a skateboard. The principle by which most conventional skateboards steer was developed long ago in connection with roller skates (see, for example, U.S. Pat. No. 244,372, which discloses roller skates having wheel assemblies that face one another and further provide that each axle is permitted to move in a limited arc. Such an assembly provides that when pressure (a rider's weight) is applied to one side of the skate or board, the wheels on that same side move both closer to the board and closer toward each other, while the wheels on the opposite side of the skater or board mover further from the board and further from each other. In short, bringing the wheels closer together on one side facilitates turning on that side.
As shown in FIGS. 1 and 2 for example, a conventional skateboard includes a board 10 a front truck assembly 12 and a rear truck assembly 14. The front truck assembly 12 includes a pair of front wheels 16 and 18 that are mounted on a front axle 20. The front axle 20 is coupled to a base 22 that is attached to the underside of the board 10 and provides that the front wheels may generally move along a plane as shown at 21. The rear truck assembly 14 includes a pair of rear wheels 24 and 26 that are mounted on a rear axle 28. The rear axle 28 is coupled to a base 30 that is also attached to the underside of the board 10 and provides that the rear wheels may generally move along a plane as shown at 29.
The skateboard includes opposing elongated sides 32 and 34, and when a rider applies more force onto one side of the board, e.g., side 32 as shown in FIG. 2, then the wheel base distance between the front and back wheels 18 and 26 (b1) on the side 32 is smaller than the wheel base distance between the front and back wheels 18 and 26 (b2) on the side 34 as shown. This provides that the skateboard will turn in a direction associated with the side indicated at 32 due to the wheels on that side being closer together. The turning radius of such a skateboard, however, is generally rather large.
Other conventional skateboards also provide either insufficient freedom of movement or are not sufficiently stable. Published PCT Patent Application WO 2004/020059 discloses a truck assembly for a skateboard that permits the range of movement of the front truck to be adjusted. European Patent Application EP0557872 discloses a skateboard truck that is disclosed to provide improved axle rebound, in part, through the use of coil springs. U.S. Pat. No. 7,438,303 discloses a truck system that is disclosed to provide adjustment of the skateboard deck relative to the skateboard truck. U.S. Patent Application Publication No 2007/0114743 discloses skateboards that are disclosed to achieve forward propulsion from sideways movement. U.S. Pat. No. 4,930,794 discloses a skateboard toy that is disclosed to have a minimal number of parts, and is disclose to imitate turning of a “real skateboard” (col. 1, line 14) by providing that tilting of the board causes each wheel assembly to turn a small amount within limit walls. U.S. Patent Application Publication No. 2002/0067015 discloses a steerable in-line skateboard that includes forward and rear trucks that each include one wheel, and each wheel is mounted on a wheel support that rotates with respect to the board.
Each of these skateboards, however, does not provide sufficient freedom of movement (such as for example, may be required to imitate the feel of surfing on a water surfboard), while also providing a stable skateboard that is easy to use.
There remains a need therefore, for a skateboard that provides greater freedom of movement of the skateboard, and in particular for a skateboard that provides greater freedom of movement of its front wheel system yet is stable and easy to use.